Lampholders for asymmetric tubular lamps



April 21,1959 E. R. KULKA 2,883,639.;

' LAMPHOLDERS FOR ASYMMETRIC TUBULAR LAMPS Filed June 11. 1956 3 Sheets-Sheet 1 IN V EN T 0R. EUGE/V! P. A UL 444 By z mfx Ap ril 21,.1959 E. R. KULKA 2,883,639

LAMPHOLDERS FOR ASYMMETRIC TUBULAR LAMPS Filed June 11. 1956 3 Sheets-Sheet '2 FIG. 6. FIG. a. 7 "I. w 201 I 2a L i/ I)! .76 J2 '3,

H67. I FIG. 9.

INVENTOR. EUGENE R. 4/4444 4 fro 2N5? April 21, 1959 E;-R.\.KULKA 2,833,539

LAMPHOLDERSFOR ASYMMETRIC TUBULAR LAMPS Filed June 11. 1956 FIG. 10.

FIG. ll

- IN V EN T 0R. EUGENE 2. 4 6/4444 BY 3 Sheets-Sheet 3 /ff v United States Patent 2,883,639 LAIVIPHOLDERS FOR ASYNIME'IRIC TUBULAR LAMPS Eugene R. Kulka, Mount Vernon, N.Y., assignor to Kulka Electric Cor Mount Vernon, N.Y., a corporation of New York Application June 11, 1956, Serial No. 590,631 2 Claims. (Cl. 339-52) This invention relates to improvements in lampholder sockets for mounting gaseous discharge lamps of the asymmetric type.

The lampholders of the present invention are intended to hold and serve as sockets for a fluorescent lamp which has a longitudinal groove running along one side of the glass tube thereof. Such a lamp emits most of its light in the area of the longitudinal groove so that the light emission is unidirectional. With lampholders of present construction it is possible to mount the lamp so that its grooves are directed in a single directional plane, that is, either horizontally or vertically. This is because the socket openings for the lamp are also not symmetrical, and the lamp cannot be turned, once mounted in the sockets.

When lamp fixtures containing the lampholders are installed, it is often required that the light emitted from the lamp be directed in various directions, depending on the particular installation. It would therefore be necessary to manufacture a variety of lampholders with their socket openings running in different directions to hold the lamp in various angular positions. This would involve considerable manufacturing expense, requiring the use of several molds for producing the various types of lampholders. It would also require the stocking of a variety of lampholders.

It is an object of the present invention to provide lampholders for an asymmetric lamp in which a single molded lampholder will serve to hold the mounted lamp in a variety of selected angular positions.

Another object of the invention is to provide lampholders of the character described in which the socket portion for receiving the lamp may be set at a selected angular position in the lampholder casing during assembly of the lampholder, and will then be held from rotation while the lampholder remains assembled.

Other objects and advantages of the invention Will be apparent in the course of the following specification when taken in connection with the accompanying drawings, in which:

Fig. 1 is a side elevation of a pair of lampholders made in accordance with the invention, with an asymmetric lamp mounted therebetween;

Fig. 2 is a section through the lamp tube, taken along line 2-2 of Fig. 1;

Fig. 3 is an exploded side elevation of the lampholder shown at the lefthand side of Fig. l, with the lampholder casing shown in central vertical section to reveal its inner construction;

Fig. 4 is a front elevation of the rear cover of the lampholder shown in Fig. 3, with its contained electrical components;

Fig. 5 is a fragmentary front elevation of the rear cover, similar to Fig. 4, but showing an alternate position of the segmental conductor stampings 38 and 39;

Fig. 6 is a central vertical section through the lampholder shown at the lefthand side of Fig. 1;

Fig. 7 is a section taken along line 7-7 of Fig. 6;

Fig. 8 is a central vertical section through the lampholder shown at the righthand side of Fig. 1;

Fig. 9 is a front elevation of the lampholder shown in Fig. 6;

Figs. 10 and 12 are side elevations of a pair of lampholders made according to the invention in a modified form, the upper portions of both lampholders being shown in section to reveal inner construction;

Fig. 11 is a section taken along line 11-11 of Fig. 10; and

Fig. 13 is a front elevation Fig. 10.

Figs. 1 and 2 show a fluorescent lamp 10 of the asymmetric type which is designed to emit the greater portion of its light in a single direction; that is, in a direction corresponding to roughly one quarter of its circumference. The lamp 10 has an elongated cylindrical glass tube 11 which is indented at one side by a line of interrupted grooves 12 extending substantially the length of the tube. As shown in Fig. 2 the grooves 12 are deep, extending substantially to the center of the tube 11. Since the grooves 12 result in bringing a large area of the phosphorcoated glass wall toward the center of the tube, the amount of radiation normally absorbed by the mercury vapor within the tube is greatly reduced. The lamp therefore emits approximately twice as much light as the conventional fluorescent lamp, the light being concentrated in the area of the grooves 12.

The lamp 10 is of the rapid start type which operate on high voltage and do not require starters. Such type of lamp has the usual hollow-head or shell 14 at each end of the glass tube 11. Each head 14 carries a projecting elongated hollow projection (not shown) in which is recessed a pair of metal wire terminals which extend within the lamp tube 11 and are connected to the lamp electrodes therein. The lampholders of the present invention each include a pair of socket contacts which contact the Wire terminals of the lamp and supply the electrical current to the lamp electrodes.

The socket assembly shown in the drawing is specifically intended for use in holding a lamp of this type in a number of selected positions, since the light emitted is directional. The socket assembly comprises a pair of lampholders 20 and 21 adapted to be mounted on a light fixture or other support in alignment with each other and facing each other, so that the lamp 10 may be supported therebetween, as shown in Fig. l.

The lampholder 20 has a hollow casing 22 closed by a rear cover 23. The rear cover 23 is secured in position by screws or rivet pins 24 extending through holes in the front wall of cover 23 and received in a post 25 projecting forwardly from the rear cover 23. Both the casing 22 and cover 23 are molded of a suitable insulating material such as urea.

The hollow casing 22 has in its front Wall a circular opening 26 which receives a cylindrical plunger 27 for sliding movement therein. The circular opening 26 communicates with an enlarged cylindrical chamber 28. As shown in Fig. 7, the chamber 28 has a series of longitudinally extending slots or grooves 30 spaced equally around its circumference. The rear end of the plunger 27 has a corresponding number of keys or splines 29 which slide Within the respective grooves 30. The keys and grooves function to prevent the plunger 27 from rotating relative to the casing 22. They also enable the plunger to be mounted in selected angular positions so as to direct of the lampholder shown in the light emitted from the lamp held thereby in selected urged by said springs to its fully extended position outside the chamber 28. In this position, the keys 29 engage the inner surface of the circular opening 26 to prevent the plunger 27 from leaving the chamber 28.

A pair of conducting strips 31 and 32, in the nature of flat metal stampings, are mounted flush against the rear cover 23, the inner surface of the rear cover being preferably grooved for receiving these strips. The strips 31 and 32 have respective bottom terminal portions 33 and 34 bent perpendicularly to project forwardly of the strips. Each terminal portion 33 and 34 mounts a screw 35 by means of which the lead wires of the lamp electrical circuit may be connected.

At the top of each conducting strip 31 and 32 is a respective integral projection 36 and 37, shown in Fig. 5, each projection containing a through aperture. A pair of identical stampings 38 and 39, in the form of segments of a circle, are fixed to the tops of the conducting strips 31 and 32. This is accomplished by means of three extrusions or dimples 40 formed in each of the stampings 38 and 39. The segmental stampings 38 and 39 are riveted to the conducting strip projections 36 and 37 by inserting one of the extrusions 40 through each of the projection apertures and peening or spinning over the end of the extrusion. The provision of three extrusions 40 on each of the stampings 38 and 39 enables the stampings to be mounted in selected operative positions, as shown in Figs. 4 and 5, for a purpose which will be presently explained.

The conducting strip terminal extensions 33 and 34 are received in slots 41 formed in the rear cover 23. The interior of casing 22 has aligned slots 42 which receive the front ends of the terminal extensions when the rear cover is assembled with the housing. The slots 41 and 42 are positioned to cooperate in holding the conducting strips 31 and 32 in rigidly mounted positions flush against the inner surface of rear cover 23.

As shown in Fig. 9, the front of the plunger 27 contains an elongated Well or cavity 45 for receiving the contactcontaining projection of the lamp. Within the well 45 is a central partition 46 separating a pair of socket contacts 47 and 48. These contacts extend through the bottom wall of the well 45 into a respective pair of bores 49 and 50. These bores 49 and 50 are shown in Fig. 7, and extend longitudinally through plunger 27.

The springs 43 and 44 extend through the respective bores 49 and 50, their front ends abutting the inner ends of the respective contacts 47 and 48. The rear ends of springs 43 and 44 are seated on the respective segmental stampings 38 and 39. It will thus be seen that the springs conduct electrical current from the conducting strips 31 and 32 to the socket contacts 47 and 48, in addition to urging the plunger 27 outwardly of the casing 22.

The lampholder 21, shown at the righthand side of Fig. l and also in Fig. 8, is identical to the lampholder 20 previously described, except that its plunger 27 is fixed immovably in its furthest inward or rearward position within the casing 22. For this purpose, keys or splines 52 of the lampholder 21 are made appreciably longer than the keys 29 of the lampholder 29. The keys 52 are substantially the same length as the grooves 30 in lampholder 20 so that said keys are not movable in said grooves, and the piston 27 is held rigidly and immovably in position with its front surface flush or substantially flush with the front surface of the casing of lampholder 21.

In mounting the lamp 10, the elongated projection on the head 14 is placed within the plunger well 45 of the lampholder 20, and the plunger 27 pressed rearwardly into the chamber 28 of lampholder 20 against the force of springs 43 and 44. The other end of the lamp may then be inserted in the well of lampholder 21. When the lamp is released, compressive action of the springs in lampholder 29 holds the lamp securely in mounted position.

With the lampholders mounted in the vertically upright 4 position shown in Fig. 1 (as may be required by a particular lamp fixture) it will be observed that the grooves 12 of the lamp face in a horizontal direction. The lamp 1% may be turned 180 so that the grooves face in the opposite horizontal direction and the lamp then mounted within the lampholders, but the lamp cannot be mounted so that its grooves are directed vertically or diagonally.

This is because the Wells 45 on the front faces of the plungers 27 are elongated, and the end projections of the lamp, which fit therein, cannot be turned therein.

For many installations of a particular fixture, it is desirable or essential that the light transmitted be directed in a vertical or angular direction, rather than a horizontal direction. The lampholders of the present invention are so constructed that they may be assembled with the axis of the piston socket 45 directed in either vertical, hori zontal or angular directions. Thus, the lamp 111 may be operatively mounted with its grooves 12 facing a number of selected directions so that the lamp may have a wider application in use.

It will be observed in Fig. 7 that the lampholder cylindrical chamber 28 has eight grooves 30 and the plunger 27 has a corresponding number of keys 29. The grooves and keys are equally spaced from one another along a circle, being 45 apart. One pair of grooves are in a horizontal plane, one pair in a vertical plane, and the other two pair are in planes directed 45 to the horizontal and vertical. In the position of the plunger 27 shown in Figs. 7 and 9, the axis of plunger socket 45 is vertical, which means that the grooves 12 of the inserted lamp will be directed horizontally in the position shown in Fig. 1. If the plunger 27 is turned in a clockwise direction as viewed in Fig. 3, through an angle of 45, the lamp 10 may be mounted therein in either of two positions, with its grooves 12 directed diagonally upward at an azimuth of 315, or diagonally downward at an azimuth of If the plunger 27 is turned further in a clockwise direction through another 45, the lamp 10 may then be mounted so that its grooves 12 will be directed vertically upward or downward.

In Fig. 9, the broken lines a, b, c and d indicate the planes along which the longitudinal axis of the plunger socket or well 45 may be set. The line a represents a horizontal plane, the line b a vertical plane, and the lines 0 and d diagonally opposite planes, i.e., planes having respective azimuths of 45 and 135. While the grooves 12 of the lamp 10 will be directed perpendicularly to the axial plane of the socket 45, it will be appreciated that the plunger 27 may be set in the assembled lampholder in a position to receive the lamp 10 with its grooves 12 directed in either direction along any of the planes indicated in Fig. 13.

Referring to Figs. 4 and 5, it will be observed that the segmental stampings 38 and 39 are made sufl'iciently short so that their ends are appreciably spaced from each other. This prevents the ends of springs 43 and 44 from bridging and shorting the conductive stampings 38 and 39 when the springs are positioned so that they are located at the ends of the segmental stampings. Fig. 4 shows the positions of the springs 43 and 44 at one end of the stampings 38 and 39. Because of the Wide spacing between the ends of the stampings, it is apparent that the springs cannot touch both stampings, even when the springs are compressed.

Because of the aforementioned wide spacing between the stampings, it will be observed that there will always be one angular plane in which the lamp cannot be mounted. In the mounted position of the stampings 38 and 39 shown in Fig. 5, for example, the spacing between the stampings is on a vertical plane, which means that the lamp 10 cannot be mounted with its grooves 12 directed horizontally in either direction, because the springs 43 and 44 will not make contact with the stampings 38 and 39. The stampings 38 and 39 are therefore provided with the three extrusions 40, permitting the stampings to be mounted in a position in which the blank space between the stampings corresponds to a position in which it would not be required to mount the lamp. For example, if a particular installation requires that the lamp be mounted with its grooves 12 directed horizontally, the stampings 38 and 39 may be mounted in the position shown in Fig. 4 (rather than that of Fig. 5) so that the spaces between the stampings are on a diagonal plane.

It will be appreciated that the provision of the three extrusions 40 on each stamping, with the extrusions spaced angularly 45 apart, enables the stampings 38 and 39 to be identical and interchangeable. Thus, only a single stamping operation is required in manufacture.

Figs. through 13 illustrate a modified form of lampholder made in accordance with the invention. The pair of lampholders 55 and 56 are similar to the lampholders 20 and 21 previously described, except that the keys and grooves are omitted. The hollow casing 57 of lampholder 55 contains an upper chamber 58 which is truly cylindrical and does not contain grooves. The front plunger opening 59, which communicates with the chamber 58, is octagonal in shape.

The plunger 60 has a forward portion 62 which also is of octagonal shape in cross-section, this forward portion extending slidably through the octagonal front open ing 59 of the casing 57. The plunger 60 also has a narrow rear portion 61 which is of circular or cylindrical shape and which is slidably received in the cylindrical chamber 58 of casing 57. The rear plunger portion 61 is of greater diameter than the octagonal front casing opening 59, so that in the fully extended position of the plunger 60, shown in Fig. 10, it abuts the rear surface of the casing front wall and acts as a stop to prevent the plunger 60 from being urged out of the casing 57.

The lampholder 56, shown in Fig. 12, is identical to the lampholder 55, except that its plunger 63 has a long cylindrical rear portion 64 and a short octagonal front portion 65. The rear portion 64 is made substantially the same length as the cylindrical chamber 58, while the length of the front portion 65 is substantially equal to the depth of the octagonal casing opening 59. Thus, in the assembled condition of lampholder 56, the plunger 63 is immovably mounted in the casing with its front surface flush with, or substantially flush with, the front surface of the lampholder casing, as shown in Fig. 12.

The octagonal shapes of the plunger and casing opening in the lampholders 55 and 56 serve the same function as the keys and grooves of the lampholders 20 and 21. That is to say, the pistons 60 and 63 are prevented from rotating within the lampholder casings, but may be set in a variety of angular positions in assembly of the lampholders, so that the light of the mounted lamp may be directed in selected directions. In Fig. 13, the broken lines indicate the planes on which the plunger socket or well 45 may be set for directing the lamp grooves 12 perpendicularly to these planes. The plane e being horizontal, the plane 1 being vertical, and the planes g and h being diagonally opposite, or at respective azimuths of 45 and 315.

While preferred embodiments of my invention have been shown and described herein, it is obvious that numerous additions, changes and omissions may be made in such embodiments without departing from the spirit and scope of the invention. For example, if a grooved tubular lamp of the type described were made with a pair of projecting terminal pins at each end, instead of recessed terminal inlead wires, the lampholders would be made in the same way except that the front of the piston would have a pair of socket holes for receiving the pins.

I claim:

1. A lampholder for mounting an asymmetric tubular lamp of the type described, said lampholder comprising a casing having a rear wall, a front opening and an internal chamber communicating with said opening, a plunger mounted in said casing and having a front portion slidably interfitting with the casing front opening and a rear portion slidably interfitting with the casing chamber, the front portion of the plunger having an elongated lamp-receiving socket opening, said socket opening containing a pair of lampholder contacts for supplying electrical current to the lamp, a pair of springs extending through the casing chamber and urging the plunger outwardly of the chamber, the springs being electrically conductive and making electrical contact with the lampholder contacts, one of the slidably interfitting portions of the casing and plunger having planar surfaces about their peripheries symmetrically arranged at 45 intervals, the planar surfaces interfitting to prevent rotation of the plunger relative to the casing, the planar surfaces being symmetrically arranged to permit the lampholder to be assembled with the plunger mounted in selected angular positions in which the axis of the elongated lamp-receiving socket opening is directed in selective horizontal, vertical and diagonal directions, a pair of longitudinall -extending conductive strips contained within said casing and located adjacent the rear wall thereof, and a pair of flat conductive stampings fixed to the ends of said strips, the stampings being in the shape of circle segments and being spaced apart at their ends, the springs being seated upon said stampings.

2. A lampholder for mounting an asymmetric tubular lamp of the type described, said lampholder comprising a casing having a rear wall, a front opening and an internal chamber communicating with said opening, a plunger mounted in said casing and having a front portion slidably interfitting with the casing front opening and a rear portion slidably interfitting with the casing chamber, the front portion of the plunger having an elongated lamp-receiving socket opening, said socket opening containing a pair of lampholder contacts for supplying electrical current to the lamp, a pair of springs extending through the casing chamber and urging the plunger outwardly of the chamber, the springs being electrically conductive and making electrical contact with the lampholder contacts, one of the slidably interfitting portions of the casing and plunger having symmetrically arranged planar surfaces about their peripheries, the planar surfaces interfitting to prevent rotation of the plunger relative to the casing, the planar surfaces being symmetrically arranged at 45 intervals to permit the lampholder to be assembled with the plunger mounted in selected angular positions in which the axis of the elongated lamp-receiving socket opening is directed in selective angular directions, a pair of longitudinally-extending conductive strips contained within said casing and located adjacent the rear wall thereof, and a pair of flat conductive stampings of identical size and shape fixed to the ends of said strips, each stamping being in the shape of a circle segment, being spaced apart at their ends, and having three extrusions spaced apart 45 along the arc of the segment, the springs being sized to be seated upon said extrusions, the end of each conductive strip having an opening receiving one of the extrusions for fixing the stamping to said strip.

References Cited in the file of this patent UNITED STATES PATENTS 

